He served as the
Jewish chaplain of
Brandeis University, the rabbi of the
Riverdale Jewish Center, an associate professor of history at
Yeshiva University, and as a founder, chairman, and professor in the department of
Jewish studies of the
City College of New York. He is currently on the faculty of
Yeshivat Chovevei Torah. He has also served as the president of the
National Jewish Center for Learning and Leadership. In 2020, Greenberg joined the faculty of the non-denominational, liberal-leaning
Yeshivat Hadar as the senior scholar-in-residence.
Ideology Greenberg's thought involves reading current
Jewish history through traditional Jewish categories of thought. He has written extensively about
the Holocaust and the historical and religious significance of the
State of Israel. He learned
Jewish thought from Rabbi
Joseph B. Soloveitchik. He has taught extensively, and a number of well-known scholars, including Rabbi
Joseph Telushkin and
Michael Berenbaum, consider him their mentor. Greenberg espouses the concept of "
Tikkun Olam" (repairing the world) as humanity working—as co-creators—with
God to improve the world. He sees the
Jewish people's
covenant with God as enjoining them to set an example for humanity's moral edification. Greenberg also suggests that the inherent image of God in every human indicates that each person possesses "infinite value, equality, and uniqueness." According to Greenberg, this means that there is no absolute
truth or 'correct' religion: "Part of every truth is the fact that an
image of God is speaking it; that is to say, a being of infinite value, equality, and uniqueness is speaking it." Only part of his post-
Holocaust theology has been published. Greenberg argues that God has broken his covenant with the Jewish people, viewing the Holocaust as a pivotal event that represents this "breaking of the covenant." The breaking event is seen as part of God's ongoing process of
tzimtzum (withdrawal) from the world. According to Greenberg, the Holocaust illustrates that the fate of the world lies in humanity's hands. If such profound evil can exist in the world, as demonstrated by the Holocaust, then it is also possible for immense good to be realized. Greenberg's theological views have been criticized by historian
David Berger. In the 1980s, Greenberg was involved in a controversial debate with the
radical right-wing rabbi
Meir Kahane. ==Personal life==